1. Field
This disclosure relates to a laminate and a method for manufacturing the same and a method for manufacturing a rotor.
The laminated core is a component of a motor. The laminated core is formed by stacking a plurality of magnetic metal sheets each of which is processed in a predetermined shape and fastening the sheets together. The motor includes a rotor and a stator each of which contains a laminated core, and is produced through a step of winding a coil on the stator and a step of attaching a shaft to the rotor, for example. Motors incorporating laminated cores have been conventionally used as driving sources for refrigerators, air conditioners, hard disc drives, and electric tools, for example, and are also used as driving sources for hybrid cars these days.
As means for fastening vertically adjacent magnetic metal pieces together in a process of manufacturing a laminated core, swaging and welding are known. These fastening means are excellent in cost and work efficiency, and have been conventionally widely used. Alternatively, when higher priorities are given to greater torque and lower iron loss of a motor, instead of swaging or welding, the magnetic metal sheets may be fastened together by using resin material or adhesive.
2. Related Background Art
WO2010/082465 discloses a method for manufacturing a laminated core 110 by temporarily binding a plurality of core sheets 50 with fixtures 120 each having a swaged area and then permanently binding the sheets with resin material. Specifically, in the method described in WO2010/082465, a segmented stator is manufactured through a step of temporarily binding together the core sheets 50 with the fixtures 120 arranged outside the laminated core 110, a step of permanently binding the laminated core 110 with an insulating resin 13 formed by die-cast molding, for example, and a step of removing the fixtures 120 from the laminated core 110 after permanently binding the laminated core 110 (see FIGS. 2 and 3 in WO2010/082465). By removing the fixtures 120 each having the swaged area from the laminated core 110 in the manufacturing process, the stator 200 having no swaged area is finally obtained.